Mechanical stoker for boiler and like furnaces.



G. DE GRAHL. MECHANICAL STOKER FOR BOILER AND LIKE FURNACES.

APPLICATION FILED JUNE 3, 1913.

Patented June 2, 1914.

3 SHEETS-SHEET 1.

COLUMBIA vLANoonAPn c0.. WASHINGTON. l). c.

G. DE GRAHL.

MECHANICAL STOKER FOR BOILER AND LIKE FURNACES.

APPLICATION FILED JUNES, 1912.

1,098,566, Patented June 2, 1914.

3 SHEETS-SHEET 2.

TIM.

p :JJ' v COLUMIIA PLANOGRAMI COHWA3IIINOTON, n14

G. DE GRAHL. I MECHANICAL STOKEB. FOR BOILER AND LIKE FURNAUES.

* APPLICATION IILED JUNBS, 1913.

r 1,098,566, Patented June 2, 1914.

3 SHEETS-$11331 3.

COLUMBIA PLANOGRAPH COUWASHINGTON D. c.

GUSTAV DE GRAI-IL, O1? ZEHLENDORF, GERMANY.

MECHANICAL STOKER FOR BOILER AND LIKE FURNACES.

Specification of Letters Fatent.

Patented June 2, 1914.

Application filed June 3, 1913. Serial No. 771,450.

in the form of stoker described in my prior 1 filed 29th October 1912, and the object of the present invention is to obtain a more convenient arrangement of rotatable scoop U. S. patent application Serial No. 728,395

mechanism specially suitable for locomotives.

The invention has also for its object to im' prove the construction of the stoker and render its operation more effective.

According to this invention the rotatable scoops are'mounted to revolve about an axis other than the axle of the locomotive or like wheels. In this way the drum and scoops are not subjected to the shocks received by the axles of the locomotive, and these shocks cannot be transferred through the scoops and drum to the grate bars. It is also of importance to leave the locomotive wheel axles free to be removed for the purposes of repairing or putting new tires on, and the present invention facilitates such dismantling of the locomotive wheel axles.

A further advantage of the present invention resides in the lightness of the parts. The drum itself may be formed of spaced grating bars and all the parts such as the casing and the like may be made considerably lighter owingto the reduction in the amount of shock to which the apparatus is subjected. The invention and the details of construction thereof will be more readily understood from the following description of one convenient form illustrated by way of example in the accompanying drawings in which Figure l is a side sectional elevation the section being taken through the fire box of the locomotive and the mechanical st cker. F ig. 2 is an end elevation partly in section. Fig. 3 is an enlarged detail view in side elevation of the drum and the parts oi the casing in the immediate vicinity thereof. Fig. 4 is a view corresponding to Fig. 8, but showing the scoops and clearing members in section. Fig. 5 is a transverse section of the drum on the line A-B of Fig. i. Fig. 6 is detail view showing the method of supporting the curved spaced grating bars which form part of the surface of the drum.

In carrying the invention into effect according to the form illustrated, the locomotive frame A, supports the wheel axles B and 29, in any well known manner. The tire box 1 is arranged to support the grate 2 and ordinary ash box 3 also in the customary manner.

The stoking mechanism, according to the present invention, consists of rotatable scoops carried by a drum 5 which is mounted independently and separately from the wheel axle B and is supported from the 10- coinotive frame A by brackets 20 which en gage the shaft 6. The drum 5 is inclosed in a casing G, to which fuel is supplied through suitable openings as hereinafter described, and discharged through other openings at the upper end of the casing. It is clear that in this way the shaft 6 is not subjected to the direct shock to which the axle B is sub jected, being cushioned therefrom by the usual springs in the well known manner. The drum 5 is formed as to part of its circumference, of curved grating bars 35 which leave spaces at diametrically opposite points, into which the movable clearing members or rakes are adapted to enter.

The clearing members or rakes 34:, are mounted about axes 33 in the neighborhood of the sides of the openings. When the rakes 34L oscillate inward about their axes 33, as shown in the lower part of Fig. 3, the scoops 32 are open. At the outermost position of the oscillation of the rakes 3 1, the scoops are closed.

On the axis cam pieces 40 (see Figs. 3 and are rigidly mounter. Against these cam pieces there bear rollers 38 oi interconnected levers 37, the interconnection being provided by the curved yoke piece 45. The purpose of this interconnection is to cause the two rollers 38 to follow the contour of the cam and operate the rakes 3a in unison so that when one rake is in closed position, the other is in open position. The drum 5 is provided at each of sides, see Fig. 5, with an internally toothed rim 7, the teeth being of ratchet form. Loosely mounted on the axis 6 and at the exterior of the drum, there are two levers 8, one at each side which carry pawls 9 pressed by springs 47 into engagement with the teeth of the ring 7. The lever 8 is caused to oscillate in the manner similar to that described in my prior U. S. application Serial No. 728,395, that is to say through a rod 10 connected to a block 11 in a slotted link 13, pivoted at 12. The link 13 i is caused to oscillate by a rod 27, eccentric strap 28, embracing the eccentric 8O mounted on the axle 29. The position of the block 11 in the slotted link 13, may be adjusted by mechanism 18 and 19 as shown. The oscillation of the lever 8 moves the drum 5 around in the direction of the arrow 31 in Fig. 3, the amount of the movement being adjusted by the mechanism described.

At one side of the drum there is provided a toothed drum 48, which engages a toothed wheel 50 on a rotatably mounted shaft 4:9. The shaft &9 also carries a driving wheel 51 connected by a chain to a driving wheel 54. fixed to a rotatable shaft 53. The rotatable shaft 53 carries a rotatable pusher 55 arranged in the chute 4, a short distance to the rear of the stoking device. The pusher 55 is caused to rotate at a speed proportional to that of the drum 5, and push the coal in the chute into the open slots or scoops 32 in the rotatable drum. Beneath the pusher 55, the lower wall is provided with two doors or resilient or yielding panels 60, 61. The panel 60 is rotatably mounted at 62, and the panel 61 is adapted to oscillate about its axis 63. These panels are held in closed position by the springs 6st and 65 respectively (see Figs. 1 and 8). If an excessively large piece of coal or stone, slate or the like enters between the wings 50 and the wall of the chute, the panels 60, 61, may if desired be held in their normally closed position by any suitable means, but I have illustrated springs by way of example only.

Beneath the drum 5, I provide an ash box 56 quite separate from the ash box proper 5 of the locomotive. The box 56 receives any ash or small particles which may pass through the grating of the drum. This ash box is easily accessible and may be readily cleaned out from time to time.

I claim 1. A mechanical stoker for boiler or like furnaces comprising a locomotive frame and axles mounted therein, a stationary furnace grate for the purpose of receiving fuel, a. fuel chute and means for raising the fuel from said chute onto the front of the fur nace grate, consisting of a. shaft secured in said locomotive frame separate from said axles, and a drum formed with one part of its circumference of curved grating bars revolubly mounted on said shaft and provided wit-h a fuel pocket having a movablebottom, means for moving said bottom outwardly from the interior to the periphery of the drum in discharging the fuel upon the grate and for moving said bottom from the periphery to the interior of said drum when receiving fuel from the fuel chute, the upper part of the periphery of said drum being adjacent to the front of said grate, and means for revolving said drum.

2'. A mechanical stoker for boiler or like furnaces comprising a stationary furnace grate for receiving the fuel, an ash-pit beneath said furnace grate, a fuel chute, and means for raising the fuel from said chute onto the front of the furnace grate consisting of a shaft, a grated drum revolubly mounted on said shaft and provided with a fuel pocket, having a movable bottom, means for moving said bottom outwardly from the interior to the periphery of the drum in discharging the fuel upon the grate and for moving said bottom from the periphery to the interior of the drum when receiving fuel from the fuel chute, the upper part of the periphery of said drum being adjacent to the front of said grate, a box directly beneath said drum and separated from said ash-pit, and means for revolving said drum.

3. A mechanical stoker for boiler or like furnaces comprising a stationary furnace grate for receiving the fuel, a fuel chute, and means for raising the fuel from said chute onto the front of the furnace grate, consisting of a shaft, a drum part of which on its circumference being formed of curved grating bars, revolubly mounted on said shaft, and provided with a fuel pocket hav ing a movable bottom, means for moving said bottom outwardly from the interior to the periphery of the drum in discharging the fuel upon the grate and for moving said bottom from the periphery to the interior of the drum when receiving fuel from the fuel chute, the upper part of the peripher of said drum being adjacent to the front of said grate, and means for revolving said drum.

4... A mechanical stoker for boiler or like furnaces comprising a stationary furnace grate for receiving the fuel, a fuel chute, ashaft, a drum, formed with part of its circumference of curved grating bars, revolubly mounted on said shaft and provided with a fuel pocket, having a movable bottom, a casing about said drum, means for supplying fuel to said casing, means for moving said bottom outwardly from the interior to the periphery of the drum in discharging the fuel upon the grate and for moving said bottom from the periphery to name to this specification in the presence of 1the interiofr of tlfie (1111111; when receiving fugel two subscribing Witnesses.

rem the uel c ute, t e upper part of t e periphery of said drum being adjacent to GUSTAV DE GRAHL' 5 the front of said grate, and means for revolving said drum.

In testimony whereof I have signed my Witnesses WOLDEMAR HAUPT, HENRY HASPER.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0. 

